In a research paper published Monday in the Proceedings of the National Academy of Sciences, a group of scientists from the University of Hong Kong analyzed 489 studies and concluded that the total mass of ants on Earth weighs about 12 megatons of dry carbon.
In other words: if all the ants were plucked from the ground and placed on a scale, they would outnumber all wild birds and mammals combined.
“It’s unimaginable,” said Patrick Schulthes, the study’s lead author and now a researcher at the University of Würzburg in Germany, in an interview with Zoom. We simply can’t imagine 20 quadrillion ants in one heap, for example. It just doesn’t work. “
Counting all of those bugs — or at least enough of them to come up with a proper estimate — involved collecting data from “thousands of authors in many different countries” over a century, Schulthes added.
To count plentiful insects like ants, there are two ways to do this: get down on the ground to sample leaf litter – or set up small traps (often just a plastic cup) and wait for the ants to slip away. Researchers have gotten their shoes dirty with surveys in almost every corner of the world, although some sites across much of Africa and Central Asia lack data.
“It’s a really global effort that goes into these numbers,” Schulthes said.
Ants, like humans, have walked across almost every continent and all kinds of habitats. According to the research team, ants that live on Earth are abundant in tropical and subtropical regions, but they can be found almost everywhere except in the coldest parts of the planet.
Or as a famous author and ant pathologist (which means ant scientist) E.O. Wilson Once you put it: “No matter where I go – except Antarctica or the high North Pole, and I don’t go there because there are no ants there – no matter how different human culture is, no matter how different the natural environment is, there are ants.”
The world, in fact, might be better off with all those ants. By digging tunnels, you aerate the soil and pull seeds underground to germinate. They serve as a food source for arthropods, birds, and nondescript mammals. While digger ants are annoying to homeowners, forests would be piled to the brim with dead wood without the decaying power of wood-destroying insects.
Entomologists are noticing a worrying decline in insect numbers outside of ants in Germany, Puerto Rico and elsewhere. Habitat destruction, pesticides, and climate change contribute to this potential but the debate remains “bugpocalypse. More than 40 percent of insect species may become extinct. According to a 2019 studywhere butterflies, bees and beetles face the greatest threat.
Scientists aren’t sure if ant numbers are declining. “Frankly, we have no idea,” Schulthes said.
This is the next research question the team wants to answer. “We have not yet attempted to show this time shift in abundance,” Sabine Naughten, an entomologist and co-lead author of the study, told Zoom. “This will be something that will happen next.”
For decades, scientists have been staring at ant farms in laboratories to test theories about animal behaviour. Ant scientist Wilson who Die Last year, he used his insights into ants to help explain the genetic basis of cooperation between animals and underscore the sheer biodiversity of life worth preserving.
In the 1990s, he ventured a rough guess at the number of ants on Earth with fellow biologist Bert Holdupler. Their estimate was about 10 quadrillion – on the same order of magnitude as the last and most stringent estimate published on Monday.
“In E.O. Wilson’s case, he was simply a very smart guy,” Schulthes said. “He knew a lot about ants and had an inner feeling, basically.”